> Summary
A borrowing from Latin; originally partly modelled on a French lexical item, and partly modelled on a German lexical item.
Etymon: Latin heuristicus.
Ultimately < post-classical Latin heuristicus (1728 or earlier), irregularly < the stem of ancient Greek εὑρίσκειν to find (see Eureka int.) + post-classical Latin -isticus -istic suffix.
As noun originally after French †héuristique (1768 in the passage translated in quot. 1770 at sense A.1; now heuristique); compare German Heuristik (1750 or earlier).